Includes: Next Level Offset Picatinny Scope Mount Materials: 6061 Aircraft Grade Aluminum Compatibility: AR-15, Rifles with Picatinny rails Weight: 5.00 oz Diameter: 1 inch, 30mm or 34mm Length: 5.50 in Base Length: 3.00 in Color: Black Warranty: Lifetime Monstrum Next Level Series Offset Scope Mounts offer the same ruggedness and reliability as our previous scope mounts but with an integrated anti-cant level bubble to check for level alignment of your rifle before each shot. Imperfect vertical alignment of your scope when shooting introduces scope cant error - horizontal drift of your shots due to cant. An anti-cant level bubble corrects for this issue, allowing you to quickly ensure for proper alignment of your rifle.